I have an error when adding the email address, it states that it is invalid. What should I do? Emails are sent as from "WordPress". How do I change that?

 In the emails settings, you might see a message indicating that the email address does not seem valid.  In the email headers "From" and "Reply-to", it is required to provide a name and the associated email. A full email address has the following format: "Name <email@domain.com>". For example: "Maestrel <hotel@maestrel.com>". Here is an example of how it will look like:

If your emails are sent with "WordPress" as sender, it means that the email template was created before the HBook version where the full address requirement was added. By default, if there is no name associated with the email address of the sender, WordPress set it as "WordPress". To change the name used to send the email, enter a full email address in the "from" field in HBook > Email template. You will change it as shown in the screenshot above.